LONDON (AP) — Britain's deputy prime minister accused Israel on Monday of carrying out "deliberate vandalism" by continuing to build settlements on land the Palestinians hope will form part of a future state.

In an escalation of Britain's previous condemnations of Israeli construction, Nick Clegg warned that continued settlement building is jeopardizing prospects for a peace deal.

"Once you've placed physical facts on the ground that makes it impossible to deliver something that everyone has for years agreed is the ultimate destination. ... It is an act of deliberate vandalism to the basic premise on which negotiations have taken place for years and years and years," Clegg said, referring to settlement construction.

Clegg was speaking alongside Palestinian President Mahmoud Abbas, who also was holding talks in London with Prime Minister David Cameron and Foreign Secretary William Hague — both of whom have previously expressed concern about settlements.

"The continued existence of illegal settlements risks making facts on the ground such that a two-state solution becomes unviable," Clegg said.

He said that continued construction would "do nothing to safeguard the security of Israel itself, or of Israeli citizens."

"This is exactly what we wanted to hear officially from the government of the United Kingdom," Abbas told reporters, speaking through a translator.

Israeli Foreign Ministry spokesman Yigal Palmor said Clegg's choice of language would do little to help attempts to restart peace talks. "It would be much better to contribute to peace by encouraging the fragile revival of Israeli-Palestinian talks rather than engaging in gratuitous bashing," Palmor said.

Cameron, who met later with Abbas at his official Downing Street residence, warned that time is "running out for the two-state solution unless we can push forward now."

Israeli-Palestinian peace talks stalled in 2009 over the issue of Israeli settlement construction in the West Bank and east Jerusalem, areas that Israel captured from Jordan in the 1967 war. It is territory the Palestinians envision as part of their future state.

Negotiators from the two sides began meeting again in Jordan on Jan.3 in the hope of restarting substantive talks, but disagreements have already surfaced over a deadline for progress on initial discussions.

"We are optimistic about those negotiations and at the same time we hope that there will be something tangible as a result of these negotiations," Abbas said. "Of course, time is of the essence — there must be speed, we must be fast in achieving those things because the settlements and the whole thing will go on."

The Palestinians insist they won't continue talks unless Israel stops building in the West Bank and east Jerusalem. Israel has said the issue of settlements will be solved once there are agreed-upon borders.

"Settlements have to stop in order for us to be able to continue our negotiations, to come to some sort of solution, and a solution which will encompass the vision of the Palestinian state to come in the future," Abbas said.

In December, European members of the U.N. Security Council said that Israel's acceleration of construction work had sent "a devastating message" and called for an immediate halt.